Surface-mounted electrical connectors most often have some form of hold-down means for securing the connector to a surface of a printed circuit board or the like. The hold-down means may be provided for permanent securement of the connector or for temporarily maintaining the connector during reflow or wave soldering procedures for permanently interconnecting terminals of the connector with circuit traces on the board. Such hold-down means may be provided by mounting pegs which are integral with the connector housing or by separate hold-down devices or clips. A typical arrangement is to provide the mounting pegs or clips with a bifurcated configuration, along with outwardly projecting hooks or barbs for engaging the opposite surface of the printed circuit board, whereby the pegs or clips can be yieldingly inserted through holes in the board and snappingly engage the opposite side of the board to hold the connector onto the one surface of the board.
One of the problems with hold-down means of the character described above, is associated with the fact that the thickness of a given circuit board may vary, if for no other reason than simple manufacturing tolerances. Consequently, although the electrical connector may be held onto the surface of the printed circuit board, if the board is too thin, the securement may not be sufficiently tight to maintain reliable interengagement between the terminals means of the connector and the circuit traces or solder pads of the printed circuit board which, in turn, will result in unreliable solder connections. In other words, during a reflow or wave soldering process, it is desirable to have the terminal means of the connector to be in steady engagement with the solder pads of the printed circuit board. If a loose securement of the connector with the board is effected by the particular hold-down means, these electrical interconnections often are unreliable or, in fact, defective. In the alternative, the solder joints may initially be reliable, but subsequently fail due to stresses incurred because the hold-down means did not securely hold the connector to the board.
Prior art mounting pegs which are integral with a connector housing do not solve the problem identified above, as associated with printed circuit boards of varying thicknesses. Consequently, separate hold-down means, such as screws or bolts often have been employed to hold a connector securely to the surface of the printed circuit board. However, such means as screws or bolts involve separate or additional assembly steps which are not very cost effective and may be difficult to perform in compact high-density environments.
It would be desirable to provide a hold-down means which is effective in response to a simple mounting procedure, such as with conventional bifurcated/hooked mounting pegs, but which can accommodate printed circuit boards of varying thicknesses. This invention is directed to that end and to solving the problems identified above.